make widget_data a function instead of an S3 method as it is very unlikely to be customized.
make widget_dependencies a function instead of an S3 method as it is very unlikely to be customized.
make widget_html a function instead of an S3 method. user can define {{name}}_html to override default. (thanks @jjallaire)
Merge branch 'master' into refactor/remove-s3-methods
move call to widget_dependencies inside closure returned from makeShinyOutput
Merge pull request #18 from ramnathv/refactor/remove-s3-methods

Refactor/remove s3 methods